Family: Secoviridae

Genus: Stralarivirus

Distinguishing features

Members of the genus Stralarivirus have a bipartite genome, two capsid proteins (CPs), and strawberry latent ringspot virus is transmitted by nematodes; phylogenetic analysis places members of this genus as a distinct lineage of the family Secoviridae, close to the members of the genera Torradovirus (CP) and Cheravirus (Pro-Pol) (Dullemans et al., 2020).

Virion

See discussion under family description.

Genome organisation and replication

Similar to comoviruses, stralariviruses have two CPs, one large and one small (Dullemans et al., 2020). The genome of stralariviruses is bipartite and the genomic organization is similar to that of comoviruses, although a N-terminal coding domain is lacking within the polyprotein encoded by RNA2. The proteinase of stralariviruses is distinct from that of other viruses in the family in that it does not seem to have a conserved His or Leu in the active site. In addition, the cleavage site recognized by the stralarivirus proteinase is unique (Table 3.Secoviridae). Similar to some nepoviruses, extensive sequence identity between RNA1 and RNA2 is found in the 5ʹ-UTRs, as well as in the 5ʹ-end of the putative coding region.

Biology

See discussion under family description.

Species demarcation criteria

See discussion under family description.